In Chicago in mid-twentieth century amid the haze and smoke of urban renewal and the sounds of the wrecking balls and bulldozers, there lived two men, both street-savvy, one Black, one Irish, one young, one old and both leaders of their clans. Each ruled with an iron fist. Each embodied the fighting spirit of the turbulent 1960s. One was David Barksdale, the Black Disciples leader, a Black youth club that would give birth to America's largest street...